In automotive engines, vacuum developed within the intake manifold or produced by a vacuum generator (e.g., a vacuum pump, aspirator, ejector, or evacuator) is routinely used to power pneumatic accessories such as power brake boosters. On/off operation of the generator and/or accessory is frequently controlled by a gate valve in which a rigid gate is deployed across a conduit to stop the flow of a fluid (in this exemplary application, air) through the valve. Within automated or “commanded” valves, the gate is typically actuated by a solenoid and opened or closed in response to an electrical current applied to the solenoid coil. These solenoid-powered gate valves also tend to include a coil spring, diaphragm, or other biasing element which biases the gate towards an unpowered, ‘normally open’ or ‘normally closed’ position. Since the biasing force must overcome frictional forces resisting movement of the gate in order to return it to its normal position, and since the solenoid mechanism must overcome both these same frictional forces and any biasing force in order to move the gate to an actively-powered position, frictional forces tend to dictate much of the required solenoid operating force, i.e., the more friction, a larger/more powerful solenoid is required.
Gate valves must satisfy a number of performance requirements, including offering minimal flow resistance when in the flow position, minimal leakage around the gate when in the no flow position, and to not offer a means for the debris entrained in the gas flowing into the valve to reside between any moving and stationary surfaces. An improvement would offer minimal impact of the flow capacity of the gate and reduce debris ingress. There is a need for a gate design that can minimize these undesirable effects.